Why does SPDIF basically suck?

[sandyk]

Well implemented Coax SPDIF can sound markedly better than most USB implementations , although it's bandwidth is inadequate for recent DSD implementations, where there is a limited amount of material available, and not in popular music either.

There is no reason why Coax SPDIF's bandwidth couldn't be markedly improved these days if there was a will to do so.

[sandyk]

11 minutes ago, Fitzcaraldo215 said:

I think that currently, USB 2.0, if competently engineered,  is perfectly capable of delivering audio as good as it gets, without fancy cables or add on gizmos.

 

 

A vast amount of feedback in other areas of the forum suggests that this has yet to be achieved.

[sandyk]

1 hour ago, Pete-FIN said:

When compared witch one sounds better, well implemented Coax SPDIF or well implemented USB? I am in the impression that well implemented USB would be better.

 

EDIT ... when listening PCM music files.

 

The only way to get well implemented USB to outperform well implemented Coax SPDIF , is to remove the degrading influence of the PC's internal +5V SMPS, and replace it with clean low noise power via preferably an external battery derived +5V supply, which has no capacitive effects back to A.C. mains earth, and use a higher quality USB cable of the shortest possible length ,where there is vastly improved isolation between the D+ and D- leads and the incoming power leads.

 Well implemented Coax SPDIF assumes the use of the correct 75 ohms BNC plugs and sockets, as well as quality isolation transformers at both ends .

BTW, the best USB cable is NO USB cable, just a modified USB-A male to USB-A  female adaptor .

 It is also possible for USB memory sticks powered via a  clean external supply to work with a modified USB adaptor where +5V and screen are not connected through. This helps to remove possible earth loops with desktop PCs as the 0 volts and screen of USB memory sticks are internally connected together, and the PC's internal 0 volts is connected to mains earth.

 In this case I use a USB Regen, but I need to insert the USB memory stick into the Regen AFTER the adaptor is plugged in and the PSU is turned on , in order for the USB memory stick to be recognised by Windows 10.

 In the attached photo, the bottom cable is replaced by the adaptor.

[sandyk]

2 hours ago, Fitzcaraldo215 said:

Why should I care what you or they think?

 

 Likewise !

[sandyk]

2 hours ago, Fitzcaraldo215 said:

What could possibly be better than total control of the totally buffered d-a process by the DAC master clock?

 

Improving the Signal Integrity BEFORE it is exported!

 

GI = GO

[sandyk]

6 hours ago, Ralf11 said:

and does it suck for Redbook, or only for high bit rates?

 

 

 

 Coax SPDIF is fine up to it's typical limitation of 24/192.

With today's technology it is capable of being taken much further, but  most recent developments have been made in the area of USB audio, which has then facilitated the use of high res DSD that wouldn't have been otherwise possible.

 

Most members of the general public still wouldn't even know what DSD audio is though!!!

[sandyk]

19 minutes ago, Panelhead said:

The transmitters and receivers used in audio applications may not handle 12 GHz, the cable is not the problem.

 

 Yes, I realise that.

[sandyk]

7 minutes ago, esldude said:

Only in Oz and a neighboring continent down under.

 

We shall see Dennis, we shall see ! 

 Perhaps on your side of the Equator it all gets sucked into a Clockwise Vortex ?

[sandyk]

7 hours ago, One and a half said:

After 6000 posts, you should know by now?

 

 Surely > 6,000 posts in just over 18 months is a record for this forum ?

[sandyk]

46 minutes ago, plissken said:

 

A vast amount of sighted evaluation you mean. Validation has yet to happen. 

 

 Despite what you may wish to believe, not ALL C.A. members use sighted evaluation of the products they test !

[sandyk]

28 minutes ago, Fitzcaraldo215 said:

Ok, fine.  But, which ones, and how many?  And, if your point is that the inherent superiority of spdif, etc. over asynch USB is manifest in each and generally EVERY case, how many and which different and specific implementations did they test under unsighted, bias controlled conditions?

 

 If you wish to know, simply because you refuse to accept that many members still obtain improved results using additional measures, you ask them !!!

[sandyk]

43 minutes ago, Fitzcaraldo215 said:

Is is that all ya got besides "many"?  It seems not.

 

 The sad fact remains that many people like yourself will still refuse to even accept the results of properly performed DBTs if the results don't go the way you insist they should have.

 Is it any wonder that most members who report subjective findings couldn't be bothered to even try and provide the level of proof that members like yourself so often demand ?

[sandyk]

29 minutes ago, Ralf11 said:

back to TOSLINK and SPDIF - how bad are they?

 Properly implemented Coax SPDIF works very well up to 24/192 for 2 channel stereo.

Toslink, through a better than average system sounds inferior to well implemented Coax SPDIF, partly due to the extra conversion stages necessary at both ends, and bandwidth limitations (and possibly S/N too?) of many Toslink receivers.

Quite a few members do however report an improvement when a more expensive Glass Toslink cable is used.

IIRC, even wgs recommends the use of a glass Toslink cable ?

[sandyk]

3 hours ago, Ralf11 said:

I will request deletion of further off topic or trolling posts by you

 

Requesting deletion of off topic posts is fine, provided that it is done for ALL members, including yourself, such as the 1st post on page 3 which was not warranted.

 

 

 

[sandyk]

45 minutes ago, Superdad said:

What's the source?  TOSLINK or S/PDIF from a computer motherboard?

 

And if the Toslink or S/PDIF source is from a quality  internal Audio card, using further processing and cleaner power , not from the Motherboard itself ?

[sandyk]

3 hours ago, Summit said:

 

They use a coax cable with BNC connectors. SPDIF use the same 75 Ohm coax cable and this is a thread about “Why does SPDIF basically suck”.  

 

 And Coax SPDIF should, for best performance , also use 75 ohm BNC connectors (including the sockets) at both ends of the 75 ohm cable.

[sandyk]

2 hours ago, mansr said:

S/PDIF also lets you do things like split the signal and feed multiple receivers at the same time. Admittedly not a typical thing to do, but if you do need to, it's possible. With USB it's pretty much impossible.

 

Even my old MF X-DAC V3 permits feeding another DAC via Coax SPDIF.

[sandyk]

9 hours ago, adamdea said:

Ooh I used to have one of those.

 So did another couple of friends of mine.

However, their performance was WAY below that of their claims and those of most reviewers. However, they improved markedly with a good low noise dual rail external power supply instead of the A.C. wallwart, the addition of voltage regulators for the analogue section, and as you can see in the photo, a .3PPM 24.576MHZ TCXO powered by a variation of the PFM " Flea"  low noise supply to it.

However , they did a pretty decent job in the Digital area.

[sandyk]

1 hour ago, beerandmusic said:

 

i think spdif sounds better than usb if you have a noisy computer...if that has been addressed, then usb can sound as good or better.

 

SPDIF sounds better if it comes from a good internal soundcard, not the motherboard.

[sandyk]

1 hour ago, Fitzcaraldo215 said:

Anticipating your likely answer, my Regen is out of the signal path gathering dust.  Do you want to buy it back?

 

Try using the Amber Regen with downloaded .flac files when converted to .wav/aiff  and saved to USB memory, and compare the SQ results with a direct conversion to .wav without the USB Regen.

The results will of course depend on just how good the rest of your system is.

 

That's best done using a USB memory stick, with the Regen powered via a12V Li Ion battery, and plugged into a USB2.0 port using an adaptor with both +5V and shield not connected through. (Use of +12V won't hurt the Regen with a light load like a USB memory stick.)

[sandyk]

5 hours ago, Summit said:

 

Most, but obviously not all here, believe that a better source give you better sound because of less noise and jitter etc. If you want to use a standard computer and optical direct out from it do that I don’t care.

 

 How electrically quiet the computer is DOES matter !

Standard MacMini's and cheap laptops with their generic SMPS don't cut it in the SQ stakes.

However, others are likely to disregard the experiences of many MacMini users who have changed to using a Linear PSU from Uptone as purely anecdotal !

[sandyk]

19 minutes ago, Ralf11 said:

 

isolate the output to the DAC, then get back to me

 

 The output to the DAC that I use for my PC audio IS isolated, as can clearly be seen in the photo of my modified Musical Fidelity X-DAC V3 that I previously posted. The 2 Coax SPDIF sockets are also isolated from the metal chassis as can be readily seen.

 

[sandyk]

47 minutes ago, Ralf11 said:

and?

 

It's your GUTB style thread.

You fill in the blanks !

[sandyk]

3 hours ago, Panelhead said:

Did make a better coax SPDIF cable recently. Used a 20” section of Belden 4505R 4K, UHD cable and crimp on Amphenol connectors that are listed as being 4K, UHD, 12 GHZ. Sounds the same as the Canare L-5CFB cable and Canare crimp on connectors it replaced. 

 

 How much difference did it make compared with something like a Belden RG59U cable with decent 75 ohm BNC connectors on both ends ? (Belden RG 59U appears to have an attenuation of < 0.5dB at 1GHz and 3 feet length.)